Hi Forum. I'm in communication with BMS manufacturers about how best to configure 32 prismatic cells for a marine application. System voltage of 48 although the vast majority of loads are 12. Redundancy is important so we are thinking about qty. 2 16S1P strings with DC-DC converters isolating each string. Are there any examples of such Victron configurations in the wild that I can study ?
I found an Orion BMS ( this is confusing given Victron DC-DC converters also called Orion ) document with some mention of such a configuration, but relatively few details. Within document the following diagram which I find an elegant solution.
I was hoping for the integration of BMS data on Victron monitoring solution with a vendor like REC BMS, but they responded to parallel strings with a master-slave solution as shown below.
Still looking for examples or more specifics on the DC-DC converter solution if somebody knows of resources. Thank you.
Orion BMS can also run in a master-slave config.
The reason you don't need a DC-DC battery strings is because once the are joined both strings should be at identical voltages. You still have redundancy if you have a failure in 1 string but you should get them back to the same voltage before rejoining the strings, else you will see huge currents as the equal out.
Hi @Sven Nurber
Best to make one string at 48 volt, and a separate 12V battery for the 12V DC users. you can charge the 12V battery from the 48V battery.
do not use dc-dc converter per string, that won't work and is not needed.
Thanks for answering Daniël. Be nice if somebody can elaborate on what is involved with such a solution. DC-DC converters seem the most elegant solution for parallel strings to me, but I don't really know what is involved.
Sven
Hi Sven, it is not, the image you showed if typically for high voltage battery systems, for low voltage you'd need very big and expensive dc-dc converters, and a system that can work with them / control them.
Ask yourself: -why would you want multiple strings?
This forum is not the place to explain how to build your own batteries, please consult an expert on that.
